用户名: 密码: 验证码:
昌宁—孟连缝合带火山岩地球化学及岩石成因
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
昌宁-孟连带是三江造山带最重要的蛇绿混杂带之一,其北延至藏东碧土,南接泰国清迈地区的Nan-Uttaradit带,直达马来西亚的本通-劳忽带,该蛇绿岩带代表了晚古生代在冈瓦纳大陆东北缘发育的古特提斯大洋的主支残留。本文通过对昌宁-孟连带乌木龙-铜厂街、干龙塘、弄巴、民乐和小定西五个剖面火山岩地质学、岩相学、微量元素与同位素地球化学的详细分析,探讨了岩石地球化学特征及其成因,并对本区古特提斯洋盆构造演化进行了总结与恢复,主要取得如下进展:
     (1)乌木龙-铜厂街超基性岩高镁、低钙,总体显示了高程度局部熔融后亏损型残留地幔橄榄岩特征。铜厂街拉斑玄武岩为富集型MORB,来源于小洋盆构造环境,而碱性玄武岩为洋岛型岩浆作用产物,源区氧逸度高,有富集组分加入。模拟计算表明碱性玄武岩是由富集型石榴石二辉橄榄岩和亏损型尖晶石二辉橄榄岩按一定比例混合发生1%~3%的部分熔融形成。
     (2)弄巴拉斑玄武岩具有富集型洋脊玄武岩(E-MORB)的特征,产于一个MORB与HMU型富集地幔相混合的弱氧化源区环境,基本没有地壳物质的混染。模拟计算表明弄巴拉斑玄武岩形成压力15-20Kbar,是地幔橄榄岩经过大约0.2-0.25%的部分熔融形成的。弄巴碱性玄武岩具有OIB的成因特征,为一个大洋板内热点部分熔融的产物,模拟表明它的形成压力大于25Kbar,是原始地幔橄榄岩经过0.1%左右的部分熔融形成的。
     (3)干龙塘拉斑玄武岩来源于氧逸度较低的亏损型地幔源区,受到地壳物质的明显混染。非实比批式熔融模拟结果表明干龙塘拉斑玄武岩经历了低压(小于1.4Gpa)和高程度(F大于10%)部分熔融,源区残留有方辉橄榄岩。
     (4)民乐和小定西中基性火山岩都属于后碰撞弧火山岩,都是原来残存于深部地幔的富含挥发分的大洋岩石圈残片发生熔融的产物。前者岩浆源区为一个氧逸度较低的还原环境,为中低度的部分熔融产物,源区存在角闪石、金红石、石榴子石等矿物相,分馏熔融模型模拟表明民乐火山岩大致相当于地幔橄榄岩1.573-3.377%的局部熔融产物;而后者具有强度大多旋回的喷发特点,源区有与熔体保持平衡的石榴子石、斜方辉石矿物相,经历了较低程度的熔融,模拟显示部分熔融程度为1.2516-1.8951%。
     (5)昌宁-孟连乃至整个东南亚地区曾发育一个广阔的古特提斯洋,它经历了大洋裂开、洋壳产生、俯冲萎缩直到两侧的Sibumasu和思茅地块碰撞造山的完整威尔逊旋回过程,由此发育了一套具有各个阶段洋幔印记的火山岩记录,是对东冈瓦纳大陆东北部边缘裂解作用的一种响应,对于探讨三江地区古生代以来的板块构造格局和洋陆转化机制研究具有重要的意义。
Changning-Menglian suture zone is considered as one of the most important ophiolite melange belts in Sanjiang orogeny, which extends northward to Bitu belt in eastern Tibet, connecting southward to Nan-Uttaradit belt in Thailand, and finnally reaches the Bentong-Raub suture in Malaysia. It represents the residue of main branch of Paleo-Tethyan ocean located in northeastern margin of Gondwana continent in late Paleozoic. Field geology, petrography, trace elements and isotopic geochemistry were adopted in volcanic rocks sampled from Wumulong-Tongchangjie, Ganlongtang, Nongba, Minle and Xiaodingxi areas to discuss petrological geochemistry and petrogenesis. This thesis also summarizes and recovers the tectonic evolution of Paleo-Tethyan oceanic basin, and the main conclusions can be drawn as follows:
     (1) The ultramafic rocks in Wumulong-Tongchangjie areas show high magnesium and low calcium. As a whole, it represents the characteristic of residual mantle rocks after the partial melting with high proportion. The tholeiites in Tongchangjie are enriched MORB and originated in a small oceanic basin, while the alkaline basalts were generated in oceanic island, and some enriched components were added in sources with high oxygen fugacity. The simulation shows alkaline basalts were formed by mixing enriched garnet lherzolite and depleted spine lherzolite with certain ratio which gave rise to partial melting at the proportion of 1%-3%.
     (2) The tholeiites in Nongba areas show the features of Enriched MORB, which derive from a weakly oxidative source mixed with MORB and HIMU. What's more, the source is not contaminated by crust basically. The simulation reveals the tholeiites in Nongba areas were derived from partial melting at the ratio of 0.2%~0.25%, and they were formed at the pressure of 15-20 Kbar in mantle source. In addition, The alkaline basalts generated in ocean island, which were the products of partial melting of the oceanic intraplate hotspot. The simulation represents it was generated from partial melting of mantle peridotites at the proportion of 0.1% in higher pressure than 25 Kbar.
     (3) The tholeiites in Ganlongtang areas were derived from depleted mantle source with low oxygen fugacity, which were obviously contaminated by crustal materials. Batch melting shows the tholeiites in Ganlongtang areas were generated from partial melting of mantle source with residual harzburgite above 10% proportion in pressure of 15-20 Kbar.
     (4) Meso basaltic volcanic rocks in Minle and Xiaodingxi areas were proved to form in the settings of post-collisional arc, which were derived from partial melting of residual slab of oceanic lithosphere rich with volatile matters. The former derived from low or moderate partial melting of reductive mantle source with amphibole rutile and garnet risidues. Fractional melting simulation reveals volcanic rocks in Minle areas generated from 1.573~3.377% proportion partial melting of mantle peridotite. But the volcanic rocks in Xiaodingxi areas have the characteristics of multicycle eruption with high intensity, and the magma keeps balance with orthorhombic pyroxene and garnet residual mineral phases in sources. The simulation shows the volcanic rocks in Xiaodingxi area were derived from partial melting of 1.2516~1.8951% with low degree.
     (5) There existed a wide tethyan ocean in Changning-Menglian area and even all over the southeast Asia, which underwent a whole Wilson cycle including oceanic breakup, generation of oceanic crust, subduction and collision between the Sibumasu and Simao terrane. Hence fingerprint of oceanic mantle in every stages was recorded by the volcanic records, which is also a response for the breakup in northeatern border of Gondwana. And it plays a key role in researching on the plate tectonic framework and the transformational mechanism between ocean and continent in Sanjiang area in late paleozoic.
引文
Aldrich M J, Chapin C E, Laughli A W. Stress history and tectonic development of the Rio Grande Rift, New Mexico.Jourourl of Geophysics Research,1986,91:6199-6211
    Baksi A K. Search for a deep-mantle component in mafic lavas using a Nb-Y-Zr plot. Canadian Journal of Earth Science,2001,38:813-824
    Barry T L, Kent R W. Cenozoic magmatism in Mongolia and the origin of central and east Asian basalts.In:Flower M F J,Chung S L, Lo C H and Lee T Y,eds. Mantle Dynamics and Plate Interactions in East Asia.American Geophysical Union, Geodynamics Series,1998,27:347-364
    Boudier F,Nicholas A,Ildefonse B. Magmachambers in the Oman Ophiolite:fed from the top and the bottom. Earth and Planetary Science Letters,1996,144:239-250
    Coleman R G. Ophiolites.Springer-Verlag,Berlin Heidelbery,1977
    Coleman R G. Tectonic setting for ophiolite obduction in Oman. Journal of Geophysics Research,1981,86:2497-2508
    Condie K C. High field strength element ratios in Archean basalts:a window to evolving sources of mantle plumes? Lithos,2005,79:491-504
    Condie K C. Episodic continental growth and supercontinents:a mantle avalanche connection? Earth and Planetary Science Letters,1998,163,97-108
    Condie K C. Incompatible element ratios in oceanic basalts and komatiites:tracking deep mantle sources and continental growth rates with time.Geochemistry,Geophysics,Geosystems,2003,4(1)
    Condie K C. Geochemical changes in baslts and andesites across the Archean-Proterozoic boundary: Identification and significance. Lithos,1989,23(1-2):1-18
    Fitton J G,Saunders A D, Norry M J. Thermal and chemical structure of the Iceland plume. Earth and Planetary Science Letters,1997,153:197-208
    Fram M S, Lesher C E. Geochemical constraints on mantle melting during creation of the North Atlantic basin. Nature,1993,363:712-715
    Garland F, Turner S, Hawkesworth C. Shifts in the source of the Parana basalts through time. Lithos,1996,37:223-243
    Green T H. Experimental studies of trace-element partioning applicable to igneous petrogenesis:Sedona 16 years later.Chemical Geology,1994,117:1-36
    Hada S, Bunopas S, Ishii K, et al. Rift-drift history and the amalgamation of Shan-Thai and Indochina/East Malaya Blocks. In:Dheeradilok P,Hinthong C, Chaodumrong P, et al, eds. Proceedings of the International Conference on Stratigraphy and Tectonic Evolution of Southeast Asia and the South Pacific, Bangkok, Thailand,1997,273-286
    Hardarson B S, Fitton J G. Increased mantle melting beneath Snaefellsjokull volcano during late Pleistocene glaciation. Nature,1991,353:62-64
    Henderson, P. Inorganic geochemistry. Pergamon Press, Oxford,1982,214-227.
    Hergt J M, Peate D W, Hawkesworth C J. The petrogenesis of Mesozoic Gondwana low-Ti flood basalts. Earth and Planetary Science Letters,1991,105:134-148
    Jahn B M, Wu F Y, Lo C H, et al. Crust-mantle interaction induced by deep subduction of the continental crust:geochemical and Sr-Nd isotopic evidence from post-collisional mafic-ultramafic intrusions of the northern Dabie complex, central China. Chemical Geology,1999,157:119-146
    Jian P, Liu D Y, Kroner A, et al. Devonian to Permian plate tectonic cycle of the Paleo-Tethys Orogen in southwest China (Ⅱ):Insights from zircon ages of ophiolites, arc/back-arc as semblages and within-plate igneous rocks and generation of the Emeishan CFB province.Lithos, 2009,113(3/4):767-784
    Jian P, Liu D Y, Kroner A, et al. Devonian to Permian plate tectonic cycle of the Paleo-Tethys Orogen in southwest China(Ⅰ):Geochemistry of ophiolites,arc/ack-arc assemblages and within plate igneous rock.Lithos,2009,113(3/4):748-766
    Kerr A C, White R V,Saunders A D.LIP reading:Recognizing oceanic plateaus in the geological record. Journal of Petrology,2000,41:1041-1056
    Kusky T M. Introduction of the book-Precambrian ophiolites and related rocks.Developments in Precambrian.Geology,2004,(13):1-34
    Kyle R M,Charles E L. Paleoproterozoic mafic dike swarms of northeast Laurentia:products of plumes or ambient mantle? Earth and Planetary Science Letters,2004,225:305-317
    Mahoney J J, Frei R,Tejada M L G, et al.Tracing the Indian Ocean mantle domain through time:Isotopic results from old West Indian, East Tethyan, and South Pacific seafloor. Journal of Petrology,2005,39 (7):1285-1306
    Marc M H. Mantle solidus:Experimental constraints and the effects of peridotite composition. Geochemistry,Geophysics,Geosystems,2000,Ⅰ:Paper number 2000GC000070
    Metcalfe Ⅰ. Allochthonous terrane processes in Southeast Asia Philosophical Transactions of the Royal Society of London A331,1990,625-640.
    Metcalfe Ⅰ. Gondwanaland dispersion, Asian accretion and evolution of Eastern Tethys. Australian Journal of Earth Sciences,1996,43:605-623
    Metcalfe Ⅰ. Late Palaeozoic and Mesozoic palaeogeography of Southeast Asia. Palaeogeography,Palaeoclimatology,Palaeoecology,1991,87:211-221
    Metcalfe I. Palaeomagnetic research in Southeast Asia,progress problems and prospects.Exploration Geophysics,1994,24:277-282
    Metcalfe Ⅰ. Palaeozoic and Mesozoic geological evolution of the SE Asian region multidisciplinary constraints and implications for biogeography. In:Robert H, Jeremy D H,Eds.Biogeography and Geological Evolution of SE Asia,1998,25-41
    Metcalfe Ⅰ. Palaeozoic and Mesozoic tectonic evolution and palaeogeography of East Asian crustal fragments:the Korean Peninsula in context. Gondwana Research,2006,9:24-46
    Metcalfe Ⅰ. Permian tectonic framework and palaeogeography of SE Asia. Journal of Asian Earth Sciences,2002,20 (6):551-566
    Metcalfe Ⅰ.The Bentong-Raub suture zoneJour of Asian Earth Sciences,2001,18:691-712
    Metcalfe I.The ancient Tethys oceans of Asia:How many? How old? How deep? How wide? Uneac Asia Papers,1999,1:1-9.
    Moores E M. Pre-1Ga(Pre-Rodinia) ophiolites:their tectonic and environmental implications. Geological Society of American Bulletin,2000,114:80-95
    Muller D,Groves D. Potassic igneous rocks and associated gold copper mineralization. Berlin:Springer,1997,11-40
    Muller D, Rock N M, Groves D I.Geochemical Discrimination Between Shoshonitic and Potassic Volcanic Rocks in Different Tectonic Settings:a Pilot Study. Mineralogy and Petrology,1992,46:259-289
    Nicolas A. Evidence from the Oman ophiolite for active mantle upwelling beneath a fast-spreading ridge. Nature,1994,370:51-53
    Niu Yaoling. Mantle melting and melt extraction processes beneath ocean ridges:evidence from abyssal peridotites. Journal of Petrology,1997,38(8):47-73
    Ormerod D S, Hawkesworth C J, Rogers N W, et al. Tectonic and magmatic transitions in the Western Great Basin USA. Nature,1988,333(26):349-353
    Pearce J A. Geochemical fingerprinting of oceanic basalts with applications to ophiolite classification and the search for Archean oceanic crust.Lithos,2008,100:14-48
    Pearce J A. The role of sub-continental lithosphere in magma genesis at destructive plate margins. in: Hawkesworth,et al,Eds.Continental Basalts and Mantle Xenoliths. Nantwich Shiva,1983,230-249
    Pearce J A,Lippard S J,Roberts S. Characteristics and tectonic significance of supra-subduction zone ophiolites. In:Kokelaar B P, Howells M F, Eds.Marginal Basin Geology.Geology Society of London,Special Publication,1984,16:77-89
    Peltonen P,Manttari I,Huhma H. Archean Zircons from the mantle:the Jormua Ophiolite revisited. Geology,2003,31:645-648
    Ray W K, John G F. Mantle sources and melting dynamics in the British Palaeogene igneous province. Journal of petrology,2000,41 (7):1023-1040
    Robertson A, Shallo M. Mesozoic-Tertiary tectonic evolution of Albania in its regional Eastern Mediterranean context.Tectonophysics,2000,316:197-214.
    Robertson A H. Development of concepts concerning the genesis and emplacement of Tethyan ophiolites in the Eastern Mediterranean and Oman regions. Earth-Science Reviews,2004,66:331-387
    Robertson A H. Overview of the genesis and emplacement of Mesozoic ophiolites in the Eastern Mediterranean Tethyan region. Lithos,2002,65:1-67
    Searle M P,Cox J. Tectonic setting,origin and obduction of the Oman ophiolite. Geological Society of American Bulletin,1999,111:104-122
    Shuhab D. K.,Khalid M. The application of remote sensing techniques to the study of ophiolites. Earth-Science Reviews,2008,89:135-143
    Sun S S, McDonough W F. Chemical and isotopic systematics of oceanic basalts:implications for mantle composition and processes. Geology Society of London,Special Publication,1989,42:313-345
    Tsuru A, Walker R J, Kontinen A, et al. Re-Os isotopic systematics of the 1.95 Ga Jormua ophiolite complex, northeastern Finland. Chemical Geology,2000,164 (1-2):123-141
    Vander W D,Bodinier J L.Origin of the recrystallisation front in the Ronda peridotite by km-scale pervasive porous melt flow. Contribution to Mineralogy and Petrology,1996,122(4):387-405
    Wilson M. Igneous petrogenesis. London:Unwin Hyman Press,2007,133-150
    Wilson M. Igneous Petrogenesis.London:University Hyman Press,1989,153-190.
    Winchester J A, Floyd P A. Geochemical discrimination of different magmas series and their differentiation products using immobile elements.Chemical Geology,1977,20:325-343.
    Zindler A, Hart S R. Chemical Geodynamics. Annual Review Earth Planet Science,1986,14:493-571
    Zou H B, Zindler A, Xu X S,et al. Major, trace element and Nd-Sr and Pb isotope studies of Cenozoic basalts iu SE China:Mantic sources, regional variations and tectonic significance. Chemical Geology,2000,171:33-47
    段向东,李静,曾文涛,等.昌宁-孟连带中段干龙塘构造混杂岩的发现.云南地质,2006,25(1):53-62
    范蔚茗,彭头平,王岳军.滇西古特提斯俯冲碰撞的岩浆作用记录.地学前缘,2009,16(6):291-302
    冯庆来,杨文强,沈上越.泰国北部清迈地区海山地层序列及其构造古地理意义.中国科学D辑,2008,38(11):1354-1360
    李朋武,高锐,崔军文,等.西藏和云南三江地区特提斯洋盆演化历史的古地磁分析.地球学报,2005,26(5):387-404
    李曙光.蛇绿岩生成构造环境的Ba-Th-Nb-La判别图.岩石学报,1993,9(2):146-157
    刘本培,冯庆来,Chonglakmani C.,等.滇西古特提斯多岛洋的结构及其南北延伸.地学前缘,2002,9(3):161-171
    刘本培,冯庆来,方念乔,等.滇西南昌宁-孟连和澜沧江带古特提斯多岛洋构造演化.地球科学:中国地质大学学报,1993,18(5):529-539.
    刘晔,柳小明,胡兆初,等.ICP-MS测定地质样品中37个元素的准确度和长期稳定性分析.岩石学报,2007,23(5):1203-1210
    莫宣学,邓晋福,董方浏,等.西南三江造山带火山岩-构造组合及其意义.高校地质学报,2001,7(2):1-108.
    莫宣学,路凤香,沈上越,等.三江特提斯火山作用与成矿.北京:地质出版社,1993,7-234.
    莫宣学,沈上越,朱勤文,等.三江中南段火山岩蛇绿岩与成矿.北京:地质出版社,1998,1-105
    彭头平.澜沧江南带三叠纪碰撞后岩浆作用、岩石成因及其构造意义.中国科学院广州地球化学研究所,博士学位论文,2006
    沈上越,冯庆来,刘本培,等.昌宁-孟连带洋脊、洋岛型火山岩研究.地质科技情报,2002,21(3):13-17
    沈上越,冯庆来,刘本培,等.三江地区南澜沧江带火山岩构造岩浆类型.矿物岩石,2002,22(3):66-71
    史仁灯,支霞臣,陈雷丁,等.Re-Os同位素体系在蛇绿岩应用研究中的进展.岩石学报,2006,22(6):1685-1695
    史仁灯.蛇绿岩研究进展、存在问题及思考.地质论评,2005,51(6):681-693
    孙雷鸣.中国及邻区地幔三维结构高分辫率体波层析成像.成都理工大学,硕士学位论文,2005
    魏君奇,王晓地,庄晓,等.澜沧江缝合带吉岔蛇纹岩中闪长岩和俄咱辉长岩中锆石SHRIMPU-Pb定年及其地质意义,岩石学报,2008,24(6):1297-1301
    吴根耀.藏东碧土地区古特提斯主洋盆中的亚速尔型洋岛玄武岩.地质通报,2006,25(6):772-781
    吴根耀.藏东左贡地区碧土蛇绿岩:古特提斯主洋盆的地质记录.地质通报,2006,25(6):685-693
    闫全人,王宗起,刘树文,等.南三江特提斯洋扩张与晚古生代东冈瓦纳裂解:来自甘孜蛇绿岩辉长岩的SHRIMP年代学证据.科学通报,2005,50(2):158-166
    杨嘉文,严平兴.南特提斯滇西带石炭-二叠纪构造古地理格局.地球科学:中国地质大学学报,1990,15(4):379-406
    杨开辉,莫宣学.滇西南晚古生代火山岩与裂谷作用及区域构造演化.岩石矿物学杂志,1993,12(4):297-311
    杨学明,杨晓勇,陈双喜.岩石地球化学.合肥:中国科学技术大学出版社,2000,140-141.
    张保民,沈上越,莫宣学,等.云南省景谷岔河地区火山岩及其构造环境.地质科技情报,2004,23(1):5-10.
    张彩华,刘继顺,刘德利.滇西南澜沧江带官房地区三叠纪火山岩地质地球化学特征及其构造环境.岩石矿物学杂志,2006,25(5):377-386.
    张旗,李达周,张魁武.云南省云县铜厂街蛇绿混杂岩的初步研究.岩石学报,1985,1(3):1-14
    张旗,钱青,王焰.蛇绿岩岩石组合及洋脊下岩浆作用.岩石矿物学杂志,2000,19(1):1-6
    张旗,钱青,王焰.造山带火成岩地球化学研究.地学前缘,1999,6(3):113-120
    张旗,周德进,赵大升.滇西古特提斯造山带的威尔逊旋回:岩浆活动记录和深部过程讨论.岩石学报,1996,12(1):17-28
    张旗,周国庆.中国蛇绿岩.北京:科学出版社,2001,1-182
    张翼飞,段锦荪.滇西蛇绿岩带地质构造演化与澜沧江板块缝合线研究.昆明:云南科技出版社,2001,1-101
    赵振华.关于岩石微量元素构造环境判别图解使用的有关问题.大地构造与成矿学,2007,31(1):92-103
    郑中.峨眉山大火成岩省的地球化学特征及其动力学指纹.中国科学院地球化学研究所.硕士学位论文,2006
    钟大赉.滇川西部古特提斯造山带.北京:科学出版社,1998,25-103
    朱勤文,莫宣学,张双全.南澜沧江古特提斯演化的岩浆岩证据,特提斯地质,1999,23:16-29
    朱勤文,张双全,谭劲.南澜沧江结合带火山岩岩浆成因-洋脊、洋岛与弧岩浆作用的性质.现代地质,1999,13(2):137-142
    朱勤文,张双全,谭劲.南澜沧江结合带火山岩岩浆成因.现代地质,1999,13(2):137-142.
    朱勤文,张双全,谭劲.确定南澜沧江缝合带的火山岩地球化学证据.岩石矿物学杂志,1998,17(4):298-307.
    朱勤文.滇西南澜沧江带云县三叠纪火山岩大地构造环境.岩石矿物学杂志,1993,12(2):134-143
    朱勤文.滇西南云县三叠纪火山岩组合及系列的厘定及其构造意义,现代地质,1993,7(2):151-159

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700